Numerous mechanisms exist to convert a fuel source into heat, either in an indoor or outdoor domestic environment, which may then be used for the secondary purpose of cooking food and/or heating liquids. One specific type of stove is known as a “rocket stove,” which is an efficient cooking stove that generally features a simple high-temperature combustion chamber in communication with a vertical chimney, as well as a heat exchanger designed to transfer heat to where it is needed (e.g., to a cooking pot). The combustion chamber/chimney combination ensures proper air draft into the combustion chamber and an almost complete, high-temperature combustion of natural fuels (e.g., wood, pine cones, dried grasses) burning within the chamber. As fuel burns, convection draws new air into the combustion chamber from below and, due to the fact that heat rises, evacuates heated smoke or exhaust from the fire through the chimney. Under the right conditions, the acceleration of air flow from the restricted combustion chamber, or firebox, up and out the chimney causes a roaring sound, rather like that of a rocket engine.
FIGS. 1A-1F show a number of examples of existing rocket-type stoves in that each combines a combustion chamber and a chimney to exhaust smoke.